07-09-2011, 01:46 PM
Looking from the underside of the radio you count pins starting at the first pin to the left of the space or locating key and going clockwise.
You can get tube information from Nostalgia Air as well. There are a lot of inexpensive digital meters available, so inexpensive that it doesn't cause grief if you burn one up. But after burning up 3 or 4 of 'em, I bought one for around $30 that autoranges and tests diodes, capacitance, and I havent' destroyed it yet.
If you need a clearer copy of the schematic or service data, you can get one from Chuck, the co-moderator for a modest fee.
Anyway, in your set, the little tubes should show very low ohms between pins 1 and 7. The medium 117Z3 should show a few more ohms between pins 3 and 4. The 3Q5 should show continuity betwewen 7 and 8 and also between 8 and 2. It is not necessary to remove the tubes to do this test. If you do remove any tubes, label them because sometimes the numbers rub off. Unless you plan to take up the hobby, you can get a whole set of tubes for this radio for a whole lot less than even a modest tube tester in working condition.
In any case, all the paper capacitors in the set need to be replaced, not just the electrolytics. And you will find instances where resistors have drifted up beyond the 20% tolerance considered normal. As they only cost pennies, and most of the time you have to disconnect one end to get a reading, I usually just replace them. I usually order a few extras of the values that are needed time after time, and sometimes my stash is sufficient to do a job without suffering a shipping fee for just a couple of items.
One more thing with this set, unless you are considering cobbling together a battery pack you can remove that troublesome interlock switch that was used when you wanted to plug the power cord in. You'll see what I mean when you get into it.
You can get tube information from Nostalgia Air as well. There are a lot of inexpensive digital meters available, so inexpensive that it doesn't cause grief if you burn one up. But after burning up 3 or 4 of 'em, I bought one for around $30 that autoranges and tests diodes, capacitance, and I havent' destroyed it yet.
If you need a clearer copy of the schematic or service data, you can get one from Chuck, the co-moderator for a modest fee.
Anyway, in your set, the little tubes should show very low ohms between pins 1 and 7. The medium 117Z3 should show a few more ohms between pins 3 and 4. The 3Q5 should show continuity betwewen 7 and 8 and also between 8 and 2. It is not necessary to remove the tubes to do this test. If you do remove any tubes, label them because sometimes the numbers rub off. Unless you plan to take up the hobby, you can get a whole set of tubes for this radio for a whole lot less than even a modest tube tester in working condition.
In any case, all the paper capacitors in the set need to be replaced, not just the electrolytics. And you will find instances where resistors have drifted up beyond the 20% tolerance considered normal. As they only cost pennies, and most of the time you have to disconnect one end to get a reading, I usually just replace them. I usually order a few extras of the values that are needed time after time, and sometimes my stash is sufficient to do a job without suffering a shipping fee for just a couple of items.
One more thing with this set, unless you are considering cobbling together a battery pack you can remove that troublesome interlock switch that was used when you wanted to plug the power cord in. You'll see what I mean when you get into it.
